package main

import (
	"crypto/md5"
	"crypto/rand"
	"encoding/hex"
	"fmt"
	"net/http"
	"time"
)

func randomToken(length int) string {
	b := make([]byte, length)
	rand.Read(b)
	return hex.EncodeToString(b)
}

func genKey(length int) []byte {
	b := make([]byte, length)
	rand.Read(b)
	return b
}

func md5hex(s string) string {
	hash := md5.Sum([]byte(s))
	return hex.EncodeToString(hash[:])
}

func (app *App) GetCookie(r *http.Request, name string, dst interface{}) error {
	cookie, err := r.Cookie(name)
	if err != nil {
		return err
	}
	return app.CookieHandler.Decode(name, cookie.Value, dst)
}

func (app *App) SetCookie(w http.ResponseWriter, name string, v interface{}, exp int) error {
	if encoded, err := app.CookieHandler.Encode(name, v); err != nil {
		return err
	} else {
		cookie := &http.Cookie{
			Name:     name,
			Value:    encoded,
			Path:     "/",
			HttpOnly: true,
			MaxAge:   exp,
		}
		http.SetCookie(w, cookie)
		return nil
	}
}

func ago(t time.Time) string {
	delta := time.Since(t)
	if delta < time.Minute {
		return fmt.Sprintf("%ds ago", int(delta/time.Second))
	} else if delta < time.Hour {
		return fmt.Sprintf("%dm ago", int(delta/time.Minute))
	} else if delta < 24*time.Hour {
		return fmt.Sprintf("%dh ago", int(delta/time.Hour))
	} else if delta < 5*24*time.Hour {
		return fmt.Sprintf("%dd ago", int(delta/(24*time.Hour)))
	} else {
		return t.Format("Jan 2")
	}
}